1 public static void main(String[] args)
2 {
3 Scanner input = new Scanner(System.in);
4 int n = input.nextInt();
5 int[] a = new int[n];
6
7 a[0] = 0; //不使用第一个位置
8 for(int i = 1; i < a.length; i++)
9 a[i] = (int)(Math.random() * 100);
10 //System.out.println(Arrays.toString(a));
11 long start = System.currentTimeMillis();
12 heapsort(a, a.length - 1);
13 long end = System.currentTimeMillis();
14 //System.out.println(Arrays.toString(a));
15 System.out.println(end - start);
16 //10000000个测试数据用时1050ms 100000000个测试数据用时11500ms
17 }
18
19 public void static heapsort(int[] a, int n)
20 {
21 for(int i = n / 2; i >= 1; i--)
22 sink(a, i, n);
23 while(n > 1)
24 {
25 int temp = a[n];
26 a[n--] = a[1];
27 a[1] = temp;
28 sink(a, 1, n);
29 }
30 }
31
32 public static void sink(int[] a, int k, int n) //最小堆化
33 {
34 while(k <= n / 2)
35 {
36 int min_index = k * 2;
37 if(min_index + 1 <= n && a[min_index + 1] < a[min_index])
38 min_index++;
39 if(a[k] > a[min_index])
40 {
41 int temp = a[k];
42 a[k] = a[min_index];
43 a[min_index] = temp;
44 k = min_index;
45 }
46 else
47 break;
48 }
49 }
